In many contexts, there is a need for easily-opened containers. In many physical applications, there are also requirements that the opened container may be readily resealable. As a rule, the requirement of ready reclosure prevails in situations where the container is gradually emptied of its contents in individual stages. Such batchwise emptying of a container is often employed when the container is used for the storage of foods.
A further requirement placed on a container for the above-outlined purposes is that it must, as far as is possible, be of a construction which safeguards against unintentional opening. In particular, in physical applications in which the lid of the container is provided with a weakened portion, for example, a circumferential weakened zone, there may be a risk of such intentional opening when the lid portion inside the weakened zone is exposed to compressive forces.